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Dévastation-class Ironclad Floating Battery
The ''Dévastation''-class ironclad floating batteries were built for the attack of Russian coastal fortifications during the Crimean War. France had intended to build ten of these vessels, but in the time available was only able to construct five in French shipyards, of which the first three took part in the attack on Kinburn in 1855, and served in the Adriatic in June–July 1859 during the Italian war. All five were stricken from the navy list between 1867 and 1875 and subsequently scrapped. Design and development Design work on the ironclad floating batteries was ordered by Emperor Napoleon III after the Battle of Sinope in 1853, informed by the experience of the French Navy from the conflict. They were designed with a shallow draft so that they could attack Russian coastal forts. The ships had an overall length of , a beam of and a draft of . They displaced . The ''Dévastation'' class was powered by a single two-cylinder direct-acting steam engine that used steam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devastation-class Ironclad
The two British ''Devastation''-class battleships of the 1870s, and , were the first class of ocean-going capital ship that did not carry sails, and the first which mounted the entire main armament on top of the hull rather than inside it. The ships were designed by Sir Edward Reed, whose concept was to produce short, handy ships of medium size as heavily armed as possible with a good turn of speed, that could attack and destroy an opponent without much risk of being damaged during the process. Design and development The Admiralty Design Board set forth the requirements for the ocean-going monitors. These included the requirement of two twin 12-inch gun turrets capable of firing 600-pound shells with a 280-degree firing arc. The turrets would require 14-inch armour protection, with the machinery spaces and shell rooms protected by 12-inch-thick armour. Further, to reduce the interference with the main guns, no masts or sails were needed. The ships would need two steam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Navy
The French Navy (, , ), informally (, ), is the Navy, maritime arm of the French Armed Forces and one of the four military service branches of History of France, France. It is among the largest and most powerful List of navies, naval forces in the world recognised as being a blue-water navy. The French Navy is capable of operating globally and conducting expeditionary missions, maintaining a significant Standing French Navy Deployments, overseas presence. The French Navy is one of eight naval forces currently operating Fixed-wing aircraft, fixed-wing aircraft carriers,Along with the United States Navy, U.S., Royal Navy, U.K., People's Liberation Army Navy, China, Russian Navy, Russia, Italian Navy, Italy, Indian Navy, India, and Spanish Navy, Spain with its flagship being the only Nuclear marine propulsion, nuclear-powered aircraft carrier outside the United States Navy, and one of two non-American vessels to use Aircraft catapult, catapults to launch aircraft. Founded in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
18-pounder Long Gun
The 18-pounder long gun was an intermediary calibre piece of naval artillery mounted on warships of the Age of Sail. They were used as main guns on the most typical frigates of the early 19th century, on the second deck of third-rate ships of the line, and even on the third deck of late first-rate ships of the line. Usage As the 18-pounder calibre was consistent with both the French and the British calibre systems, it was used in many European navies between the 17th and the 19th century. It was a heavy calibre for early ships of the line, arming, for instance, the main batteries of in 1636. From the late 18th century, the French Navy used the 18-pounder in three capacities: as the main gun on frigates, as the battery on the upper gundeck of two-deckers, and lastly on the top deck of three-deckers. French frigates began carrying the 18-pounder under Louis XV, when the two frigates, originally designed to carry 24-pounders, were equipped with it; at the time, a typical frig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smoothbore
A smoothbore weapon is one that has a barrel without rifling. Smoothbores range from handheld firearms to powerful tank guns and large artillery mortars. Some examples of smoothbore weapons are muskets, blunderbusses, and flintlock pistols. The opposite of smoothbore is rifling. History Early firearms had smoothly bored barrels that fired projectiles without significant spin. To minimize inaccuracy-inducing tumbling during flight, their projectiles required an aerodynamically uniform shape, such as a sphere. However, surface imperfections on the projectile and/or the barrel will cause even a sphere to rotate randomly during flight, and the Magnus effect will curve it off the intended trajectory when spinning on any axis not parallel to the direction of travel. Rifling the bore surface with spiral grooves or polygonal valleys imparts a stabilizing gyroscopic spin to a projectile that prevents tumbling in flight. Not only does this more than counter Magnus-induced drift, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Battery
A main battery is the primary weapon or group of weapons around which a warship is designed. As such, a main battery was historically a naval gun or group of guns used in volleys, as in the broadsides of cannon on a ship of the line. Later, this came to be turreted groups of similar large-caliber naval rifles. With the evolution of technology the term has come to encompass guided missiles and torpedoes as a warship's principal offensive weaponry, deployed both on surface ships and submarines. A main battery features common parts, munition and fire control system across the weapons which it comprises. Description In the age of cannon at sea, the main battery was the principal group of weapons around which a ship was designed, usually its heavies. With the coming of naval rifles and subsequent revolving gun turrets, the main battery became the principal group of heaviest guns, regardless of how many turrets they were placed in. As missiles displaced guns both above and belo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ship Motions
Ship motions are the six degrees of freedom that a ship, boat, or other watercraft can experience. Reference axes The '' vertical/Z axis'', or ''yaw axis'', is an imaginary line running vertically through the ship and through its centre of mass. A yaw motion is a side-to side movement of the bow and stern of the ship. The '' transverse/Y axis'', ''lateral axis'', or ''pitch axis'' is an imaginary line running horizontally across the ship and through the centre of mass. A pitch motion is an up-or-down movement of the bow and stern of the ship. The '' longitudinal/X axis'', or ''roll axis'', is an imaginary line running horizontally through the length of the ship, through its centre of mass, and parallel to the ''waterline''. A roll motion is a side-to-side or port-starboard tilting motion of the superstructure around this axis. Rotational There are three special axes in any ship, called longitudinal, transverse and vertical axes. The angular movements around them—a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sail Area
A sail is a tensile structure, which is made from fabric or other membrane materials, that uses wind power to propel sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and even sail-powered land vehicles. Sails may be made from a combination of woven materials—including canvas or polyester cloth, laminated membranes or bonded filaments, usually in a three- or four-sided shape. A sail provides propulsive force via a combination of lift and drag, depending on its angle of attack, its angle with respect to the apparent wind. Apparent wind is the air velocity experienced on the moving craft and is the combined effect of the true wind velocity with the velocity of the sailing craft. Angle of attack is often constrained by the sailing craft's orientation to the wind or point of sail. On points of sail where it is possible to align the leading edge of the sail with the apparent wind, the sail may act as an airfoil, generating propulsive force as air passes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stroke (engine)
In the context of an internal combustion engine, the term stroke has the following related meanings: * A phase of the engine's cycle (e.g. compression stroke, exhaust stroke), during which the piston travels from top to bottom or vice versa. * The type of power cycle used by a piston engine (e.g. two-stroke engine, four-stroke engine). * "Stroke length", the distance travelled by the piston during each cycle. The stroke length, along with bore diameter, determines the engine's displacement. Phases in the power cycle Commonly used engine phases or strokes (i.e. those used in a four-stroke engine) are described below. Other types of engines can have very different phases. Induction-intake stroke The induction stroke is the first phase in a four-stroke (e.g. Otto cycle or Diesel cycle) engine. It involves the downward movement of the piston, creating a partial vacuum that draws an air-fuel mixture (or air alone, in the case of a direct injection engine) into the combustion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bore (engine)
In a piston engine, the bore (or cylinder bore) is the diameter of each cylinder. Engine displacement is calculated based on bore, stroke length and the number of cylinders: displacement = The stroke ratio, determined by dividing the bore by the stroke, traditionally indicated whether an engine was designed for power at high engine speeds ( rpm) or torque at lower engine speeds. The term "bore" can also be applied to the bore of a locomotive cylinder or steam engine pistons. In steam locomotives The term bore also applies to the cylinder of a steam locomotive or steam engine. Bore pitch Bore pitch is the distance between the centerline of a cylinder bore to the centerline of the next cylinder bore adjacent to it in an internal combustion engine. It's also referred to as the "mean cylinder width", "bore spacing", "bore center distance" and "cylinder spacing". The bore pitch is always larger than the inside diameter of the cylinder (the bore and piston diameter) sinc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cylinder (engine)
In an engine, the cylinder is the space in which a piston travels. The inner surface of the cylinder is formed from either a thin metallic liner (also called "sleeve") or a surface coating applied to the engine block. A piston is seated inside each cylinder by several metal piston rings, which also provide seals for compression and the lubricating oil. The piston rings do not actually touch the cylinder walls, instead they ride on a thin layer of lubricating oil. Steam engines The cylinder in a steam engine is made pressure-tight with end covers and a piston; a valve distributes the steam to the ends of the cylinder. Cylinders were cast in cast iron and later in steel. The cylinder casting can include other features such as valve ports and mounting feet. Internal combustion engines The cylinder is the space through which the piston travels, propelled by the energy generated from the combustion of the air/fuel mixture in the combustion chamber. In an air-cooled e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propeller
A propeller (often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft (ship), propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from stern sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Displacement (ship)
The displacement or displacement tonnage of a ship is its weight. As the term indicates, it is measured indirectly, using Archimedes' principle, by first calculating the volume of water displaced by the ship, then converting that value into weight. Traditionally, various measurement rules have been in use, giving various measures in long tons. Today, tonnes are more commonly used. Ship displacement varies by a vessel's degree of load, from its empty weight as designed (known as "lightweight tonnage") to its maximum load. Numerous specific terms are used to describe varying levels of load and trim, detailed below. Ship displacement should not be confused with measurements of volume or capacity typically used for commercial vessels and measured by tonnage: net tonnage and gross tonnage. Calculation The process of determining a vessel's displacement begins with measuring its draft.George, 2005. p. 5. This is accomplished by means of its "draft marks". A merchant vessel has t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
